An aircraft parked at a gate while on the ground generally requires an auxiliary power unit engine (APU) to cool or heat the aircraft, since the engines of the aircraft are not running. Several Aircraft High Pressure, Low Temperature, Ground Based Air-Conditioners or preconditioned air units (PCAir) have been proposed in the art and used in airports throughout the world. Historically, one airport gate served one aircraft at a time. Therefore, PCAir units were designed to service one aircraft at a time.
However, the rise on use of the larger wide-body aircraft has led to the development of the multiple aircraft ramp system (MARS) gate arrangement wherein two passenger loading bridge can accommodate two narrow body aircraft or one wide body aircraft. Due to the fact that the current PCAir units are designed to serve only one aircraft at a time, when two narrow body aircraft reside at the same aircraft stand position, each aircraft is serviced with the same airflow, air pressure, and temperature regardless of the type of plane or internal temperature in each aircraft. The result is under-cooled or over-cooled aircraft. Moreover, aircraft from different manufacturers have vastly different pressure and temperature requirements. By way of example, Boeing aircraft accept high air flow at 32° F., but several Airbus aircraft require air at −10° F. at very low air flow to prevent damage to the air ducts.
Moreover, aircraft from different manufacturers have vastly different pressure and temperature requirements. By way of example, Boeing aircraft accept high air flow at 32° F., but several Airbus aircraft require air at −10° F. at very low air flow to prevent the air ducts from bursting.
The use of two PCAir units to supply one aircraft is also known in the art and commonly used by airports throughout the world. U.S. patent application Ser. No. 13/257,461 provides for a PCAir unit that contains two independent air units. Each unit can be independently set for temperature because they are two separate units. However, the PCAir unit has only one single intake airstream. Similar PCAir units can be found in U.S. patent application Ser. No. 11/863,998 and a similar mobile unit can be found in CN Pat. No. 200320114412.5.
A more desirable PCAir unit would allow for independent temperature, air pressure and airflow control of each narrow body aircraft at a MARs gate. Such a PCAir unit would allow independent control of each of two or more PCAir outlets from a single unit. The desired PCAir unit system would provide independent temperature, air pressure and airflow to each narrow body aircraft in a MARs configuration, or provide appropriate temperature, air pressure and airflow to one wide body aircraft.